Äîêóìåíò âçÿò èç êýøà ïîèñêîâîé ìàøèíû. Àäðåñ îðèãèíàëüíîãî äîêóìåíòà : http://www.stsci.edu/~marel/abstracts/pdfdir/STScINewsl20_3_03.pdf Äàòà èçìåíåíèÿ: Sun Sep 21 19:41:51 2003 Äàòà èíäåêñèðîâàíèÿ: Sat Dec 22 18:32:31 2007 Êîäèðîâêà: Ïîèñêîâûå ñëîâà: meteor shower

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Spa ce T elescope Science Institute

The Cycle 12 Proposal Peer Review
Duccio Macchetto, macchetto@stsci.edu, Robert Williams, wms@stsci.edu, & Brett Blacker, blacker@stsci.edu

Overview

Ongoing Features of the Hubble Peer Review
The oversubscription of Hubble observing time and data-reduction funds remains high. Evaluating such a large number of proposals has led to some distinctive procedures followed by the panels in identify the best proposals. We expect these procedures to apply to future proposal cycles, as follows. Two -tiered TAC. In consultation with the Space Telescope Institute Council, the Director sets aside one third of the available observing time (~1,000 orbits) for large (over 100 orbits) and Hubble Treasury proposals, which the TAC evaluates. The remaining two thirds of observing time is devoted to smaller programs, which are evaluated exclusively by the individual disciplinary panels. The relevant disciplinary panels review the large and Treasury proposals, but the multi- disciplinary TAC performs the final assessment. Twin panels. Except for the solar system panel, each disciplinary panel has one or two `mirror ' panels that consider those proposals for which its own members may have some conflict of interest. This procedure minimizes loss of expertise in the discussion due to panelists recusing themselves from the evaluations. In Cycle 12, the acceptance rate for proposals with panelist PIs was the same as that for non-panelist PIs. Progressive orbit subsidy. In order to encourage panels to resist a tendency to favor smaller Continued page 3 programs because of the greater number of them that can be approved given the limited

W

ith the continuing excellent performance of the major instruments on Hubble, the science program of the telescope during Cycle 11 has been very productive. At the same time there is some uncertainty over the timing of the next servicing mission, which will install the new Cosmic Origins Spectrograph and Wide Field Camera 3. Cycle 12 observations will begin in July 2003 on an accelerated timeline in which the Institute has shortened the period between proposal submission and observations by four months. The Institute received 1,046 proposals in late January 2003 in response to the Cycle 12 Call for Proposals. This represents an oversubscription in requested orbits by more than 6 to 1, down slightly from the 1,075 proposals received in Cycle 11. The full Time Allocation Committee (TAC) and 11 disciplinary panels met in Baltimore in late March to evaluate the proposals and to recommend programs to the Director for implementation. As reported in the fall 2002 Newsletter, an external review of the Institute's TAC process was conducted last summer, which affirmed the basic integrity and effectiveness of the Hubble peer review, but which recommended certain changes in Cycle 12. (See http://www.stsci.edu/resources/ tac_assessment.) Among these changes were a loosening of institutional conflict-of-interest rules governing panelists' review of proposals, the dissemination of reviewer comments to Principal Investigators (PIs) that reflect the panel discussions, and convening an annual workshop to facilitate broad collaboration on Hubble Treasury proposals.

SUMMER



2003



Credit: NASA , NOAO, ESA , the Hubble Helix Nebula Team, M. Meixner (STScI), and T.A . Rector (NRAO). See page 6 for more information.


DIRECTOR'S PERSPECTIVE

STARS I N ASTRONOMY
Steven Beckwith, svwb@stsci.edu

he other day a friend of mine remarked casually, "It seems that all stellar astronomers over the age of 50 have gotten cranky." We had noticed a certain defensiveness in one of our colleagues who thought his interests had been marginalized among more fashionable topics often featured in the popular press. Stellar astronomy dominated the study of the universe for most of the last 400 years, and astronomers who work on stars are following a rich tradition. But a lot of us got the feeling that stars are well understood and have moved on to more exotic pursuits, leaving the stellar astronomers to rethink that rich tradition.
"Stellar " brings to mind "the best and brightest," and when I talk about astronomers who work on "stars," visions of Hollywood and all its glamour come to mind. Indeed, the importance of stars as a subject for human inquiry is embedded in the language whenever we want to describe individual achievement that stands above all the rest. So why are these "stellar astronomers" cranky? It cannot be because of any lack of success with the Hubble Space Telescope. The Cycle 12 TAC rated a stellar proposal, Fritz Benedict 's (#9879) as its highest priority this year among nearly 1100 competitors. Benedict 's team will measure the distances to Cepheid variables by direct parallax using the Fine Guidance Sensor (FGS1R) on Hubble; Howard Bond won time for a similar, albeit smaller program to recalibrate the Cepheid zero point luminosity-period (L-p) relationship following precise measurements of the distances to these important stars. Hubble is now the most precise instrument in history for measuring the positions of stars, achieving an accuracy of 0.2 milliseconds of arc (mas), about five times better than Hipparcos, the previous state - of-the -art. At that precision, several fundamental problems in astronomy come into reach for the first time. For example, the l argest uncertainty in the distance scale of the universe, expressed through H0, is the zero point calibration of the L-p relation, which Benedict and Bond can improve by a factor of a few to reduce the error in our knowedge of H0--and thus the age of the universe. Bond is using similar techniques to improve our knowledge of binary star masses as a check on stellar evolution theory. There has been a problem with some binary star systems whose components appear to have much different ages from one another when calculated by our standard theory, whereas we expect them to be coeval. Initial observations of Procyon revised the derived masses of the two stars in this binary system downward and brought the observations into agreement with theory for the first time. Bond's team is continuing with observations of several other binary systems. Stellar evolution theory is one of the most important advances of 20th century astrophysics, and its verification remains an essential underpinning for our field. ER 8 is the coolest known white dwarf in the Galaxy and hence the oldest. It is nearby and moving rapidly, and by chance it will pass within 50 mas of a background star in 2006 causing an apparent shift in the center of light by more than 8 mas owing to gravitational lensing of the star by the white dwarf. This shift is easily detectable with FGS1R , allowing Kailash Sahu and his collaborators to measure the mass of ER 8 to better than 5%. Knowing the mass of this cool white dwarf will allow them to set the best lower limit to the age of the Galaxy yet and, by extrapolation, to the universe itself. This measure of universal age is completely independent of the standard methods of cosmology and has the potential to either confirm or deny our standard model for the universe. This is not the sort of impact we expect from a



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DIRECTOR'S PERSPECTIVE
device whose main goal is to keep a spacecraft pointed in the right direction, but then Hubble continues to show its superlative capabilities in unlikely areas. Sumner Starrfield and colleagues recently had their image of the peculiar nova V838 Mon on the cover of Nature, an image so spectacular that it could displace the Eagle Nebula as Hubble's most iconic image in the public's mind. We already have T- shirts with V838 Mon that are quite popular among the T- shirt wearing crowd. (I am thinking of getting a tie with that image or maybe another hat.) The Fine Guidance Sensors don't get much respect these days, but they are quietly providing opportunities to rewrite the textbooks. FGS1R , installed during servicing mission 3a, has improved the state - of-the -art to such a degree that it opened up a number of new research areas, just as all of Hubble's new instruments have. The Cycle 12 TAC recommended programs using the FGS for 5% of the total orbits at the same time that WFPC2--the venerable camera that is responsible for 90% of the public and more than 50% of the scientific impact of Hubble--received only 2% of the time. This change once again show how servicing Hubble has expanded the range of its scientific capabilities: FGS1R improved the state - of-the -art for astrometric precision by as much as the Advanced Camera for Surveys improved imaging. Servicing Hubble gives us a lot of bang for the buck, and since it takes a lot of bucks to do it, we are pleased to get a correspondingly big bang. Our stellar astronomers have been flying stealthily below our radar screens to pick off some of the most important problems in astronomy with Hubble's unmatched accuracy. The TAC noticed, I noticed, and pretty soon, someone in the science media will notice that a field thought by its own practitioners to be less than fashionable is actually cutting a wide swath through new territory and giving the more glamorous folks a run for their money. So, if you are a stellar astronomer who is feeling cranky, you may want to take heart in the new opportunities offered by Hubble. It is going to help you rewrite the textbooks as it has with so many other fields. I, for one, will be cheering you on.

Cycle 12 Review from page 1

observing time, the Institute subsidizes the cost in orbits charged to the panel for moderate proposals (15-100 orbits). For each orbit approved above 15, an increasing fraction is charged against a pool of orbits held in reserve for the purpose. This policy has succeeded in increasing the fraction of moderate programs over the past 5 cycles. Reviewer comments . Panel feedback with information on the panel's discussion and assessment of a proposal is highly desired by most PIs--if not always valued! Each proposal is assigned a primary reviewer, who is responsible for writing his/her own review and for incorporating comments from the other secondary reviewers. The primary reviewer leads the panel discussion and edits the written comments to reflect the panel discussion. Then others--the secondary reviewers, the panel support scientist (an Institute scientist), and the panel chair-- review the comments before they are sent to the PI.

Also Notable in the Cycle 12 Peer Review
Cycle 12 continued the collaboration between the Institute, the National Optical Astronomy Observatories, and the Chandra X-ray Center on the peer review of proposals requesting resources on the Hubble and either Chandra or NOAO telescopes. The Hubble peer review can approve observing time on the above facilities it deems necessary for the science objectives of the Hubble proposal. The maximum total time that can be approved in this manner is 400 ksec on Chandra and 20 nights on NOAO telescopes. For Cycle 12, the TAC and panels recommended approval of 115 ksec on Chandra and 17.5 nights on NOAO telescopes. Proposers used the Astronomer 's Proposal Tool (APT) for Phase I and Continued Phase II submission for the first time in Cycle 12. APT enables PIs to write page 4 their proposals in a variety of text editors on different platforms and



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Cycle 12 Review from page 3

submit them in a way that results in a uniform format for all proposals. This feature was essential to our being able to shorten the time between proposal submission and scheduling observations. While we have experienced some glitches typical of the first-time use of a large software package, the Institute is committed to correcting the flaws and making APT as user friendly as possible. Specific comments on APT are welcomed and should be sent to apt-phase1@stsci.edu.

Advice to Future Proposers
The present Hubble review process is highly regarded and widely copied. We plan to use the same process in future cycles, which means future proposers should keep in mind the following advice drawn from experience. The scientific case should be of broad interest to your fellow astronomers. The most successful proposals describe the importance of the investigation to all astronomy in a convincing manner and include sufficient background information to provide a compelling context. Do not write proposals that are of interest to only a few experts in a narrow subdiscipline. Instead, present the big picture. This is an explicit evaluation criterion, and proposals are downgraded for failing to address it. Ask only for the resources you genuinely need. Justify your request for the number of targets and orbits and the need for Hubble observations. For example, even if you request observations in the ultraviolet, it may not be obvious to the reviewers why you cannot achieve the science aims of your proposal in a different wavelength range. In the infrared, justify your need for Hubble and NICMOS by comparison with adaptive optics systems on ground-based telescopes. Because of the limited number of orbits available in a cycle, many truly excellent proposals must be turned down. Nevertheless, remember that rejected PIs are in very good company and that many of these proposals succeed in future cycles.

Final Thoughts
There is no ideal process for evaluation of proposals, and the Institute remains open to new procedures that will improve our evaluation process. We are constantly assessing our procedures in response to suggestions from the Users Committee and the community. We augment or modify some aspects of our procedures every succeeding cycle. The Cycle 12 TAC made many hard decisions, which have produced the Cycle 12 science program for the Hubble. We express our appreciation to the panelists and TAC members who participated in the recent TAC process, with special thanks to Dr. Tim de Zeeuw for serving as TAC Chair for this cycle. In the accompanying tables, we list the panel and TAC members and the programs that have been approved by the Director to receive observing time and/or data reduction and archival research funds in Cycle 12.



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Cycle 12: TAC and Panel Members
Member
TAC Chair Tim de Zeeuw Solar System Panel Members Marc Buie Nancy Chanover Jean-Claude Gerard Amanda Hendrix Ralph Lorenz Karen Meech (Chair) Hal Weaver Galactic Panel Members Charles Bailyn (Chair) Bruce Balick Thomas Bania David Bennett David Charbonneau Roger Chevalier You-Hau Chu (Chair) Robin Ciardullo Constantine Deliyannis Andrew Dolphin Bruce Elmegreen (Chair) Rob Fesen Ed Fitzpatrick Jules Halpern Mario Hamuy Pat Hartigan Thomas Henning Pascale Jablonka Joachim Krautter Richard Larson Jeff Linsky Peter Martin Phil Massey David Meyer Georges Meynet Mark Morris Antonella Natta (Chair) Marc Pinsonneault James Pringle Tad Pryor John Raymond Bo Reipurth Bradley Schaefer Regina Schulte-Ladbeck (Chair) Michal Simon Ed Sion Stephen Smartt Tammy Smecker-Hane Verne Smith Alexander Tielens Todd Tripp William van Altena Ted von Hippel Don Winget Hans Zinnecker Ellen Zweibel Yale University University of Washington Boston University University of Notre Dame California Institute of Technology University of Virginia University of Illinois at Urbana - Champaign The Pennsylvania State University Indiana University System National Optical Astronomy Observatories IBM T.J. Watson Research Center Dartmouth College Villanova University Columbia University Carnegie Institution of Washington Rice University Max-Planck-Institut fur Astronomie, Heidelberg CNRS, Institute d'Astrophysique de Paris Landessternwarte Heidelberg Yale University University of Colorado at Boulder University of Toronto / Canadian Institute for Theoretical Astrophysics Lowell Observatory Northwestern University Geneva Observatory University of California - Los Angeles Osservatorio Astrofisico di Arcetri Ohio State University Cambridge University Rutgers the State University of New Jersey Smithsonian Institution Astrophysical Observatory University of Hawaii University of Texas at Austin University of Pittsburgh State University of New York at Stony Brook Villanova University Cambridge University University of California - Irvine University of Texas at El Paso Kapteyn Astronomical Institute Princeton University Yale University University of Texas University of Texas at Austin Astrophysikalisches Institut Potsdam University of Wisconsin Lowell Observatory New Mexico State University Universite de Liege California Institute of Technology University of Arizona University of Hawaii The Johns Hopkins University Applied Physics Laboratory Sterrewacht Leiden

Institution

Member
Extragalactic Panel Members Eric Agol Matthias Bartelmann Ralf Bender (Chair) Katherine Blundell Tereasa Brainerd Elias Brinks Michael Brotherton Gerald Cecil Renyue Cen Stephane Charlot Giuseppina Fabbiano (Chair) Heino Falcke Xiaohui Fan Karl Glazebrook Anthony Gonzalez Richard Green (Chair) Henk Hoekstra Deidre Hunter William Keel Jean-Paul Kneib Ken Lanzetta Simon Lilly (Chair) Lynn Matthews Patrick McCarthy (Chair) David Merritt Gerhardt Meurer Rafaella Morganti John Mulchaey Reynier Peletier Rosalba Perna Patrick Petitjean Richard Pogge Joel Primack Michael Rauch Susan Ridgway Abhijit Saha David Sanders Ian Smail Thaisa Storchi-Bergmann Michele Thornley William van Breugel Liliya Williams Rogier Windhorst Donald York Steve Zepf

Institution

California Institute of Technology / University of Washington Max-Planck-Institut fur Astrophysik Universitats-Sternwarte Munchen / Max-PlanckInstitut fur extraterrestrische Physik University of Oxford Boston University Universidad de Guanajuato University of Wyoming University of North Carolina at Chapel Hill Princeton University Max-Planck-Institut fur Astrophysik / CNRS, Institute d'Astrophysique de Paris Smithsonian Institution Astrophysical Observatory Max-Planck-Institut fur Radioastronomie/University of Nijmegen University of Arizona The Johns Hopkins University University of Florida National Optical Astronomy Observatories University of Toronto / Canadian Institute for Theoretical Astrophysics Lowell Observatory University of Alabama Observatoire Midi-Pyrynees / California Institute of Technology State University of New York at Stony Brook ETH Zurich Smithsonian Institution Astrophysical Observatory Carnegie Institution of Washington Rutgers the State University of New Jersey The Johns Hopkins University Stichting Astronomisch Onderzoek in Nederland (ASTRON) Carnegie Institution of Washington University of Nottingham Smithsonian Institution Astrophysical Observatory CNRS, Institute d'Astrophysique de Paris Ohio State University University of California - Santa Cruz Carnegie Institution of Washington The Johns Hopkins University National Optical Astronomy Observatories University of Hawaii University of Durham Universidade Federal do Rio Grande do Sul Bucknell University Lawrence Livermore National Laboratory University of Minnesota Arizona State University University of Chicago Michigan State University



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Proposals By Country
Country
Australia Austria Belgium Brazil Canada Chile France Germany India Ireland Israel Italy Japan Mexico Norway Russia Spain Sweden Switzerland The Netherlands Ukraine United Kingdom United States ESA Countries

Summary of Cycle 12 Results
Proposals
General Observer Snapshot Archival Research Theory Total Primary Orbits

Submitted
11 2 4 2 13 3 26 32 2 2 5 22 3 1 1 1 11 4 4 9 1 60 827 190

Approved
3 0 0 0 3 0 3 8 0 0 1 4 0 0 0 1 2 0 0 4 0 9 203 32

Requested Approved % Accepted ESA Accepted ESA % Total
819 74 111 42 1046 19674 170 21 41 10 242 3154 20.8% 28.4% 36.9% 23.8% 23.1% 16.0% 28 4 32 323 16.5% 19.0% 16.8% 10.2%

Proposal Acceptance Ratio

The Helix Nebula Detail

T

his cropped version of the Helix Nebula mosaic shows cometar y-filaments embedded along a portion of the inner rim of the nebula's red and blue gas ring. At a distance of 650 light-years, the Helix is one of the nearest planetar y nebulae to Earth. The composite picture is a seamless blend of ultra-sharp NASA Hubble Space Telescope (HST) Advanced Camera for Sur veys images combined with the wide view of the Mosaic Camera on the National Science Foundation's 0.9-meter telescope at Kitt Peak National Obser vator y, part of the National Optical Astronomy Obser vator y, near Tucson, Arizona Astronomers at the Space Telescope Science Institute (STScI) assembled the images into a mosaic. The mosaic was blended with a wider photograph taken by the Mosaic Camera. Credits: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgment: Bo Reipurth (University of Hawaii)



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US Proposals By State Instrument Statistics
Instruments Requested Orbits
ACS/HRC ACS/SBC ACS/WFC FGS NIC1 NIC2 NIC3 STIS/CCD STIS/FUV STIS/NUV WFPC2 Total 1914 266 11727 578 427 1866 1471 1475 2743 1516 1919 25902

State
%
4.7% 0.4% 49.7% 5.0% 3.4% 11.2% 6.4% 6.3% 8.1% 2.4% 2.3% 100.0% 54.8% 5.0%

Submitted
7 70 135 41 10 11 9 11 10 21 1 18 8 4 3 46 155 21 5 5 1 1 3 13 14 37 11 4 5 53 4 11 30 13 14 18 1 3

Approved
0 18 39 13 6 1 3 4 2 5 0 4 2 2 1 11 38 6 0 0 0 1 1 5 3 6 4 1 2 6 1 2 8 3 1 4 0 1

%
7.4% 1.0% 45.3% 2.2% 1.6% 7.2% 5.7% 5.7% 10.6% 5.9% 7.4% 100.0%

Approved Orbits
251 19 2640 268 183 597 342 333 433 126 123 5315

SubTotal

53.7% 2.2%

14.5%

21.1%

27.8% 7.4%

23.2% 2.3%

Orbits include coordinated parallel usage Excludes Pure Parallel and Snapshot Programs

Proposal and Orbit Results By Science

AL AZ CA CO CT DC DE FL GA HI IA IL IN KY LA MA MD MI MN MO NC NE NH NJ NM NY OH OK OR PA SC TN TX VA WA WI WV WY

Cosmology 31% Cool Stars 5% Galaxies 19% Hot Stars 6% ISM 9%

QAL 3% Star Formation 6% Stellar Pops 11% Solar Systems 3% AGN 7%



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Name

Institution

Type

Title

Extragalactic Programs



8
GO GO GO GO GO GO GO AR GO GO GO AR AR GO GO GO GO AR AR SNAP GO GO AR GO GO AR GO GO GO AR GO AR GO AR GO AR ACS Imaging of the Gemini Deep Deep Survey Fields: Galaxy Assembly at z = 1.5 A morphological study of EROs and sub-mm sources in a unique deep field Measuring Black Hole Masses in Double Peaked Broad Lined AGNs Probing the High Redshift Universe with Quasar Emission Lines Calibrating the Black Hole Mass Scale for Quasars Elliptical galaxies in z~1.5 clusters HST / Chandra Monitoring of a Dramatic Flare in the M87 Jet Comparing the ACS Ultra Deep Field to Low Redshift Galaxy Observations The Ages of Nuclear Star Clusters in Early-Type Spiral Galaxies A New Member of the Local Group? The rarest of sightlines: probing the metallicity of a DLA with a nearby Low Surface Brightness galaxy A Decade of AGN SEDs The low redshift Lyman-alpha forest and the intrinsic QSO continuum Anomalous Flux Ratios in Quadruple Gravitationally Lensed QSOs Are We Missing the Dominant Sites of Star Formation in Local UV-Bright Starbursts? Age-dating Star Clusters in M101 A near-IR imaging survey of sub-mm galaxies with spectroscopic redshifts The Spectral and Morphological Evolution of Galaxies The Fate of Luminous Compact Blue Galaxies: An Environmental Approach The Dusty ISM Substructure in Nearby Spiral Galaxies A Search for the Missing Baryons in Nearby Cosmic Filaments Life in the fast lane: The dark-matter distribution in the most massive galaxy clusters in the Universe at z>0.5 The mass assembly history of early-type galaxies at z~1 The role of dark matter and intracluster gas in galaxy formation and cluster evolution Nailing Down M31's Central Black Hole Numerical simulations of outflows in quasars: the microphysics of BAL winds The Upper End of the Supermassive Black Hole Mass Function: Pushing the 10 Billion Solar Mass Limit The Globular Cluster Systems of Spiral Galaxies along the Hubble Sequence Deep NICMOS imaging of HDF-South: restframe optical morphologies of high redshift galaxies Resolving Galaxy Formation and Evolution for Interpretation of HST Observations ESSENCE: Measuring the Dark Energy Equation of State A Detailed Photoionization Study of the Broad Line Region of NGC 5548 Search for Black Holes in M31 Globular Clusters Measurements of core sizes in luminous early-type galaxies Accurate and Robust Calibration of the Extragalactic Distance Scale with the Maser Galaxy NGC 4258 The Astrophysics of Star Formation & Galaxy Building in the "Middle Ages": z ~ 0 to 2

CYCLE 12: Approved Observing Program s



Roberto Abraham Omar Almaini David Axon Jack Baldwin Aaron Barth Philip Best John Biretta Michael Blanton Torsten Boeker Gregory Bothun David Bowen Michael Brotherton Scott Burles Scott Burles Rupali Chandar Rupali Chandar Scott Chapman Andrew Connolly Steven Crawford Roelof de Jong Renato Dupke Harald Ebeling Richard Ellis Richard Ellis Eric Emsellem Gary Ferland Laura Ferrarese Duncan Forbes Marijn Franx Jeffrey Gardner Peter Garnavich C. Gaskell Karl Gebhardt Alister Graham Lincoln Greenhill Timothy Heckman

University of Toronto Royal Observatory Edinburgh Rochester Institute of Technology Michigan State University California Institute of Technology University of Edinburgh, Institute for Astronomy Space Telescope Science Institute New York University Space Telescope Science Institute University of Oregon Princeton University University of Wyoming Massachusetts Institute of Technology Massachusetts Institute of Technology Space Telescope Science Institute Space Telescope Science Institute California Institute of Technology University of Pittsburgh University of Wisconsin - Madison Space Telescope Science Institute University of Michigan University of Hawaii California Institute of Technology California Institute of Technology Centre de Recherche Astronomique de Lyon University of Kentucky Rutgers the State University of New Jersey Swinburne University of Technology Universiteit Leiden University of Pittsburgh University of Notre Dame University of Nebraska - Lincoln University of Texas at Austin University of Florida Smithsonian Institution Astrophysical Observatory The Johns Hopkins University


Name

Institution

Type

Title

CYCLE 12: Approved Observing Program s



9



Luis Ho Rolf Jansen Sebastian Jester Kelsey Johnson Inger Jorgensen Igor Karachentsev Daniel Kelson Jeffrey Kenney Anton Koekemoer David Koo David Koo Konrad Kuijken Konrad Kuijken Kenneth Lanzetta Ari Laor Soren Larsen Karen Leighly Barry Madore Barry Madore Patrick McCarthy Jon Miller Edward Moran John Mulchaey Christopher O'Dea Eric Perlman Bradley Peterson Bradley Peterson Bradley Peterson Andrew Phillips Daniel Proga Douglas Richstone Susan Ridgway Bassem Sabra Vicki Sarajedini James Schombert Edward Shaya George Sonneborn S. Stanford

Carnegie Institution of Washington Arizona State University Fermilab University of Wisconsin - Madison Gemini Observatory, Northern Operations Russian Academy of Sciences, Special Astrophysical Obs. Carnegie Institution of Washington Yale University Space Telescope Science Institute University of California - Santa Cruz University of California - Santa Cruz Universiteit Leiden Universiteit Leiden State University of New York at Stony Brook Technion-Israel Institute of Technology European Southern Observatory - Germany University of Oklahoma Norman Campus Carnegie Institution of Washington Carnegie Institution of Washington Carnegie Institution of Washington Smithsonian Institution Astrophysical Observatory Wesleyan University Carnegie Institution of Washington Space Telescope Science Institute University of Maryland Baltimore County Ohio State University Ohio State University Ohio State University University of California - Santa Cruz University of Colorado at Boulder University of Michigan The Johns Hopkins University University of Florida University of Florida University of Oregon Raytheon Technical Services Company NASA Goddard Space Flight Center University of California - Davis

SNAP SNAP GO AR GO SNAP GO GO AR AR AR GO GO AR GO GO GO AR GO AR GO GO GO GO GO GO GO SNAP AR AR GO GO GO AR AR AR GO AR

A Narrow-band Snapshot Survey of Nearby Galaxies H-alpha Snapshots of Nearby Galaxies observed in F300W: Quantifying Star Formation in a Dusty Universe The Nature of the UV Excess in the Jet of 3C273 A Multi-Wavelength Study of Super Star Clusters as They Emerge From Their Birth Material Galaxy Evolution During Half the Age of the Universe: ACS imaging of rich galaxy clusters The local Hubble flow and the density field within 6 Mpc Galaxy Populations at Very Large Cluster Radii: The Outskirts of MS1054-03 at z=0.83 Ram Pressure Stripping in the Virgo Spiral NGC 4522 Morphology and Evolution of the Largest Complete Sample of X-ray Selected AGN Evolution of the Tully-Fisher Relation of High Redshift z > 1 Disks Using GOODS-N Images and Keck DEIMOS Spectra The Ages of Distant Field Galaxy Spheroids Proper motion kinematics in Galactic bulge/bar fields The mass of the Milky Way: orbits for Leo I and Leo II Photometry and Photometric Redshifts of Faint Galaxies in the Ultra-Deep Field Reverberation Mapping of the Least Luminous Seyfert 1 Galaxy NGC 4395 Young Massive Clusters in Spiral Galaxies and the Connection with Open Clusters UV Spectroscopic Observations of Luminous Narrow-line Seyfert 1 Galaxies Morphological Evolution of Galaxies from the Present to z = 0.3-0.5 M83: Calibrating the Cepheid PL Relation Archival Study of Red Galaxies in the Chandra Deep Field South Observations of Intermediate Mass Black Hole Candidate Ultra-Luminous X-ray Sources X-ray-Bright, Optically Normal Galaxies: The "Hidden" Truth The Role of Groups in the Evolution of Galaxies at Intermediate Redshifts Time Scales for Gas Transport, Star Formation, and AGN Fueling in the Born-again Radio Galaxy 3C236 The Structure and Physics of Extragalactic Jets AGN Black Hole Masses from Stellar Dynamics Structure of the Accretion Disk in the NLS1 NGC 4051 Host Galaxies of Reverberation-Mapped AGNs Nature & Evolution of Compact Galaxies in the GOODS-N Field AGN Radiation-Driven Outflows: Models vs. Observations Black Holes in Big Galaxies with Small Bulges The Evolution of the Host Galaxies of Radio-Quiet Quasars AALs in Quasars: Diagnostics of the Environment AGN in the GOODS fields: A Study of Short-Term Variability, Spectroscopy and Morphology Morphological and Structural Study of the Galaxies in Distant Cluster CL1322.5+3028 Optimization of the Tip of the Red Giant Branch Distance Estimator Probing the Halo and ISM of Low-Redshift Galaxies with Young Supernovae The Construction of Elliptical Galaxies at High Redshifts


Name

Institution

Type

Title


AR GO AR GO GO AR GO GO GO GO GO GO GO GO The Impact of Infall and Outflow Motions on the Circumstellar Envelope of Young Stars Dwarf Elliptical Galaxies in Nearby Groups: Stellar Populations and Abundances Turbulent Variability of Disk Accretion in Cataclysmic Variables Rotation in Jets from Young Stars: investigating NUV lines with very high Spectral Resolution Observing the Next Nearby Supernova Archival Studies of Main Sequence Binaries in 47 Tucanae (NGC104) An ACS/WFC H-alpha Survey of the Orion Nebula Verifying the White Dwarf Mass-Radius Relation with Sirius B The Planetary Nebula K648 in the Globular Cluster M15 UV extinction by dust in unexplored LMC environments Young Massive Clusters in M33 Boron in F Stars in the Hyades - Insights into the Li-Be Dip HST Observations of Astrophysically Important Visual Binaries Trigonometric Calibration of the Period-Luminosity Relations for Fundamental and First-Overtone Galactic Cepheids

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CYCLE 12: Approved Observing Program s



Massimo Stiavelli Lisa Storrie-Lombardi Michael Strauss Tommaso Treu Jason Tumlinson Wil van Breugel Sylvain Veilleux Bart Wakker Fabian Walter Rachel Webster Richard White Bradley Whitmore Gerard Williger Rogier Windhorst David Wittman Haojing Yan Yujin Yang Stephen Zepf Wei Zheng Wei Zheng Bodo Ziegler

Space Telescope Science Institute California Institute of Technology Princeton University California Institute of Technology University of Chicago Lawrence Livermore National Laboratory University of Maryland University of Wisconsin - Madison National Radio Astronomy Observatory University of Melbourne Space Telescope Science Institute Space Telescope Science Institute The Johns Hopkins University Arizona State University Bell Labs Arizona State University University of Arizona Michigan State University The Johns Hopkins University The Johns Hopkins University Universitats-Sternwarte Gottingen

GO GO GO AR SNAP GO GO GO GO GO GO GO GO SNAP AR GO GO GO GO SNAP GO

The environment of QSOs at the reionization epoch Morphologies of EROs and Field Galaxies in SIRTF's First Look Survey: A Rich Early Release Dataset The Host Galaxies of Type II Quasars The Lenses Structure and Dynamics (LSD) Survey: mass distribution and stellar populations of high redshift E/S0 galaxies Probing IGM Phases, Metals, and the Cosmic Web with New SDSS QSOs Giant Lya Halos Around High Redshift Radio Galaxies The Fundamental Plane of Massive Gas-Rich Mergers Intergalactic O VI absorption at redshift <0.004 Investigating the Powering Sources of Expanding Supergiant Shells in the Nearby Dwarf Galaxy IC 2574 Microarcsecond Imaging of a Gravitationally Lensed QSO: 2237+0305 Leaky IGM at z=6 or Lyman Alpha Galaxy at z=5? ACS, NICMOS, and STIS Observations of Three Ongoing Mergers A test of the foreground proximity effect at z=1.2 NIC3 SNAPs of nearby galaxies imaged in the mid-UV: the remarkable cool stellar population in late-type galaxies. Probing the Mass Distribution at High Redshift in the UDF NIC3 Imaging of z~6 Candidates in a Deep ACS Parallel Field: Finding the reionizing population and their LF Galaxy Evolution in Action: The Detailed Morphology of Post-Starburst Galaxy The Age and Mass Function of the Intermediate Age Globular Cluster System of NGC 4365 Properties of the Intergalactic Medium near the Epoch of HeII Reionization Confirmation of New Candidates for the Study of Intergalactic Helium Evolution of Scaling Relations of Field Spiral Galaxies at Intermediate Redshift

Galactic Programs

Hector Arce Taft Armandroff Philip Armitage Francesca Bacciotti John Bahcall Charles Bailyn John Bally Martin Barstow Luciana Bianchi Luciana Bianchi Luciana Bianchi Ann Boesgaard Howard Bond Howard Bond

California Institute of Technology National Optical Astronomy Observatories, AURA JILA Osservatorio Astrofisico di Arcetri Institute For Advanced Study Yale University University of Colorado at Boulder University of Leicester The Johns Hopkins University The Johns Hopkins University The Johns Hopkins University University of Hawaii Space Telescope Science Institute Space Telescope Science Institute


Name

Institution

Type

Title

CYCLE 12: Approved Observing Program s



11



Francois Boulanger Herve Bouy Terry Bridges Timothy Brown Adam Burgasser Nuria Calvet Stefan Cartledge Roger Chevalier Orsola De Marco John Debes Andrew Dolphin Andrew Dolphin Bryan Dorland Gordon Drukier Reginald Dufour Douglas Duncan Steven Federman Annette Ferguson Gary Ferland Robert Fesen Boris Gaensicke Peter Garnavich Donald Garnett Douglas Gies Douglas Gies Gerard Gilmore John Gizis John Gizis John Gizis Bertrand Goldman Karl Gordon Graham Harper William Harris Patrick Hartigan Carole Haswell William Herbst Gregory Herczeg Jeff Hester

Institut d'Astrophysique Spatiale European Southern Observatory Anglo-Australian Observatory University Corporation For Atmospheric Research University of California - Los Angeles Smithsonian Institution Astrophysical Observatory Louisiana State University & Agricultural & Medical College The University of Virginia American Museum of Natural History Pennsylvania State University National Optical Astronomy Observatories, AURA National Optical Astronomy Observatories, AURA United States Naval Observatory Yale University Rice University University of Colorado at Boulder University of Toledo Kapteyn Astronomical Institute University of Kentucky Dartmouth College University of Southampton University of Notre Dame University of Arizona Georgia State University Research Foundation Georgia State University Research Foundation University of Cambridge University of Delaware University of Delaware University of Delaware New Mexico State University University of Arizona University of Colorado at Boulder McMaster University Rice University Open University Wesleyan University University of Colorado at Boulder Arizona State University

GO SNAP GO GO GO GO GO AR GO GO AR GO GO GO SNAP GO AR GO AR GO SNAP AR GO GO GO SNAP GO GO SNAP GO GO AR GO GO GO GO AR GO

SMC Extinction Curve Towards a Quiescent Molecular Cloud Multiplicity among brown dwarfs in the Pleiades cluster Search For Metallicity Spreads in M31 Globular Clusters A Search for Water Vapor in the Atmosphere of an Extrasolar Planet T Dwarf Companions: Searching for the Coldest Brown Dwarfs Search for Core-disrupting Wide-Angle Winds Exploring Interstellar Krypton Abundance Variations at Kiloparsec Scales Stellar wind interactions around binary stars: models for planetary nebulae A tailored survey of proplyds with the ACS Finding Planets in the Stellar Graveyard: A Faint Companion Search of White Dwarfs with NICMOS CTE Corrections for WFPC2 and ACS ACS Photometric Zero Point Verification The Kinematics and Dynamics of the Material Surrouding Eta Carinae Shooting Stars: Looking for Direct Evidence of Massive Central Black Holes in Globular Clusters CIII] Imagery of Planetary Nebulae and HII Regions -- A Snap Program Experimental Proof of the Neutrino Process in SN from Boron Isotope Measurements Surveying Interstellar Carbon Monoxide Via Ultraviolet Absorption Stellar Populations in the Outskirts of M33: A Unique Probe of Disk Galaxy Formation Calculation of Fe II atomic data required for the modeling of HST observations Probing the Dynamics and Shock Physics of the Cas A Supernova Remnant Towards a global understanding of accretion physics - Clues from an UV spectroscopic survey of cataclysmic variables Transients in the Ultra-Deep Field Recombination Lines and Temperature Structure in Planetary Nebulae The Masses of the O-type Binary 15 Monocerotis Wind Accretion and State Transitions in the Black Hole Binary Cyg X-1 A snapshot survey of rich stellar clusters in the Large and Small Magellanic Clouds Ultraviolet Observations of a Very Young Brown Dwarf NICMOS Observations of Cool Brown Dwarf Doubles A Snapshot Search for Halo Very-Low-Mass Binaries Brown dwarf atmospheric variability observations The Exciting Wavelength of Extended Red Emission New Insights into Betelgeuse's Inhomogeneous Wind Establishing the Metallicity Distribution in Normal Giant Ellipticals Ultraviolet Emission from Protostellar Accretion Disks Microquasars: Outbursts and Outflows in Black Hole Accretion Flows Natural Coronagraphic Imaging of KH 15D Models of Gas in Disks of Classical T Tauri Stars ACS Monitoring of the Polarization of the Crab Nebula


Name

Institution

Type

Title



12

CYCLE 12: Approved Observing Program s



Dean Hines Jay Holberg J. Howk Jimmy Irwin Christopher Johns-Krull Christopher Johns-Krull Christopher Johns-Krull Stefan Jordan Paul Kalas Paul Kalas Charles Keyes Ivan King Christian Knigge Christian Knigge John Krist James Lauroesch Alex Lazarian Walter Lewin Michael Liu Roberto Maiolino Philip Massey Philip Massey Bruce McCollum Bernard McNamara S. Megeath Michael Meyer Roberto Mignani Yazan Momany Jon Morse Jose Munoz Edmund Nelan M. Sean O'Brien Robert O'Dell Robert O'Dell George Pavlov George Pavlov Laura Penny Geraldine Peters

Space Science Institute University of Arizona University of California - San Diego University of Michigan Rice University Rice University Rice University Universitat Tubingen, Institut fur Astronomie & Astrophysik University of California - Berkeley University of California - Berkeley Space Telescope Science Institute University of Washington University of Southampton University of Southampton Space Telescope Science Institute Northwestern University University of Wisconsin - Madison Massachusetts Institute of Technology University of Hawaii Osservatorio Astrofisico di Arcetri Lowell Observatory Lowell Observatory California Institute of Technology New Mexico State University Smithsonian Institution Astrophysical Observatory University of Arizona European Southern Observatory - Germany Universita di Padova University of Colorado at Boulder Universidad de Valencia Space Telescope Science Institute Yale University Vanderbilt University Vanderbilt University The Pennsylvania State University The Pennsylvania State University College of Charleston University of Southern California

GO GO AR AR AR GO GO GO GO GO GO GO GO GO GO GO AR AR GO SNAP GO GO SNAP AR GO GO GO GO GO GO GO GO AR GO GO GO AR SNAP

Enabling Coronagraphic Polarimetry with NICMOS STIS Observations of Orbital and Rotational Variations in the Unique Post-Common Envelope System HS1136+6646 Interstellar Cooling in the SMC: a Template for Understanding High-Redshift Star Formation The Globular Cluster-Low Mass X-ray Binary Connection in Nearby Early-type Galaxies: An Archival Study Accretion Shocks in Classical T-Tauri Stars The Distance to the Pleiades Separating Activity and Accretion in T Tauri Stars The field structure of the most strongly magnetized white dwarf PG1031+234 ACS Imaging of beta Pic: Searching for the origin of rings and asymmetry in planetesimal disks ACS detection of sub-stellar companions around Vega, Fomalhaut and beta Pic via parallax & proper motion Multi-wavelength Observations of Symbiotic Stars in Outburst The Bottom of the Main Sequence in the Old, Metal-Rich Cluster, NGC 6791 Curing the SW Sex Syndrome Uncovering the CV population in M15: a deep, time-resolved, far-UV survey of the cluster core Evolution of Young Stellar Outflows: XZ Tauri and HH 30 The Physical Character of the Smallest-Scale Interstellar Structures Flows, Turbulence, and Mixing Archival HST Studies of Six Globular Clusters NICMOS Confirmation of a Young Planetary-Mass Companion A NICMOS search for obscured supernovae in starburst galaxies The Physical Parameters and Stellar Winds of Hot, Massive Stars at High Metallicity: O-stars in the Andromeda Galaxy A He-rich O2-3 star in the LMC: Freakish Relic or Paradigm Shifter? First Spectroscopic Study of a Unique Set of Young Stars in the Orion Nebula Searching for Very Low Mass Objects in M35 Using the HST/FGS Archive How do Brown Dwarfs Form? The Origins of Sub-stellar Masses: Searching for the 'End' of the IMF Timing of the proposed optical counterpart of the 16 ms LMC X-ray pulsar PSR J0537-6910 SagDIG: a benchmark for understanding star formation in extreme low-metallicity galaxies Tracking the Homunculus and Outer Ejecta of Eta Carinae A Survey of Extinction Curves to Redshift z=1 Dynamical Masses and Radii of Four White Dwarf Stars The Distance and Mass of the Neutrino-Luminous White Dwarf PG 0122+200 Analysis of Helix Nebula Observations During the Leonids Encounter of 2002 Calibration of the ACS Emission Line Filters Far-UV Spectrum and Pulsations of PSR 0656+14: Thermal vs. Nonthermal What's The Point? Deep NICMOS Imaging of the Central X-ray Point Source in Cas A Projected Rotational Velocities of O-type Stars at Low Metallicity A SNAPSHOT Survey of Sharp-Lined Early B-Type Stars


Name

Institution

Type

Title

CYCLE 12: Approved Observing Program s



Giampaolo Piotto Steven Pravdo Francesca Primas Barton Pritzl Bo Reipurth Michael Rich Martino Romaniello Pilar Ruiz-Lapuente Steven Saar Raghvendra Sahai Raghvendra Sahai Kailash Sahu Karin Sandstrom Ravi Sankrit Divas Sanwal Ata Sarajedini Dimitar Sasselov Matthias Schreiber Kenneth Sembach Janet Simpson Stephen Smartt John Stocke Roeland van der Marel Schuyler Van Dyk Don Vandenberg Frederick Walter Barry Welsh Daniel Welty Klaus Werner Russel White Robert Williams Brian Wood Rosemary Wyse Hans Zinnecker

UniversitÞ di Padova Jet Propulsion Laboratory European Southern Observatory - Germany National Optical Astronomy Observatories, AURA University of Hawaii University of California - Los Angeles European Southern Observatory - Germany University of Barcelona Smithsonian Institution Astrophysical Observatory Jet Propulsion Laboratory Jet Propulsion Laboratory Space Telescope Science Institute University of California - Berkeley The Johns Hopkins University The Pennsylvania State University University of Florida Harvard University Observatoire de Strasbourg Space Telescope Science Institute NASA Ames Research Center University of Cambridge University of Colorado at Boulder Space Telescope Science Institute California Institute of Technology University of Victoria State University of New York at Stony Brook University of California - Berkeley University of Chicago Universitat Tubingen, Institut fur Astronomie & Astrophysik California Institute of Technology Space Telescope Science Institute University of Colorado at Boulder The Johns Hopkins University Astrophysikalisches Institut Potsdam

GO GO GO SNAP GO SNAP GO GO GO GO SNAP GO GO GO GO GO GO GO GO GO GO GO AR AR GO GO GO GO GO GO GO AR AR GO

Geometric Distances of the Galactic Globular Clusters NGC2808 and NGC6752 NICMOS Observations of the Gl 164 Companion Boron in stars of same O and Li, but different Be: testing cosmic-ray vs. neutrino spallation The Second Parameter Effect in Metal-Rich Globular Clusters: A Snapshot Study of NGC 6388 HH110: Collision between a Jet and a Cloud A Snapshot Survey of Galactic Bulge Globular Clusters Low Mass Star Formation at Low Metallicity: Accretion Rates of Pre-Main Sequence Stars in the Large Magellanic Cloud Probing the nature of Type Ia SNe through HST astrometry Whirling Dervish Dynamos: Magnetic Activity in CV Secondaries Tracking the Evolution of a Knotty, High-Speed Jet in the Carbon Star, V Hydrae Are OH/IR Stars the Youngest post-AGB stars? A NICMOS Imaging Survey Accurate Mass Determination of the Ancient White Dwarf ER 8 Through Astrometric Microlensing UV Spectroscopy of the Hot, Helium-Core White Dwarf Companion in HR 1608 Kepler's Supernova Remnant: an Imaging Study of the Blast Wave - Circumstellar Medium Interaction Optical Counterpart of the Neutron Star 1E 1207.4-5209 in PKS 1209-51/52 Supernova Remnant Main Sequence Turnoff Ages For Second Parameter Clusters in M33 OGLE-TR-56b: The Most Interesting Transiting Planet Detecting the hottest white dwarf in a dwarf nova: V446 Her as a laboratory for irradiated accretion discs The Properties of Highly Ionized High Velocity Gas in the Distant Galactic Corona and Local Group A Search for the Exciting Sources in OMC-1 through NICMOS Polarization Measurements Direct imaging of the progenitors of massive, core-collapse supernovae Probing Outflowing Winds from the Galactic Center Stellar Dynamical Models for HST Proper Motion Datasets The Local Environments of Supernovae in Archival HST Images Parallaxes of Extreme Halo Subgiants: Calibrating Globular Cluster Distances and the Ages of the Oldest Stars The Parallax of Geminga Where is the Local Hot Gas? Abundances, Dust, and Physical Conditions in the LMC ISM Iron deficiency in hot hydrogen-deficient post-AGB stars A Search for Young Binary Brown Dwarfs: Constraining Formation Scenarios and Masses Through Multiplicity Integrated Absorption- and Emission-Line Analysis of Nebulae Searching for Astrospheric Lyman-alpha Absorption Detections in the HST Archive An astrometric standard field in omega Cen A NICMOS direct imaging search for giant planets around the seven single white dwarfs in the Hyades

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Name

Institution

Type

Title

Solar System Programs


GO GO GO GO AR GO SNAP GO GO GO AR GO AR GO SNAP GO GO GO GO GO GO An Astrometric Calibration of the Cepheid Period-Luminosity Relation The Next Generation Spectral Library HST Imaging of Gravitational Lenses The Grism-ACS Program for Extragalactic Science (GRAPES) The NICMOS Parallel Observing Program Exploration of the SN Ia Hubble Diagram at z > 1.2 Tracing the History of Cosmic Expansion to z~2 with Type Ia Supernovae The Galactic Bulge Deep Field: A Planetary Transit Survey and Very Deep Stellar Mass Function GO GO The COSMOS 2-Degree ACS Survey Deep Near IR Images in the Chandra Deep Field South Ultra Deep Field

14

CYCLE 12: Approved Observing Program s



James Bell Richard French Erich Karkoschka Mark Lemmon Tariq Majeed Jean-Luc Margot William Merline Joel Parker Mark Showalter William Sparks Anne Verbiscer Harold Weaver Rogier Windhorst

Cornell University Wellesley College University of Arizona Texas A & M Research Foundation University of Michigan California Institute of Technology Southwest Research Institute Southwest Research Institute NASA Ames Research Center Space Telescope Science Institute The University of Virginia The Johns Hopkins University Arizona State University

Spectroscopy and Polarimetry of Mars at Closest Approach Saturn's rings and small moons on the eve of Cassini The Long-term Observational Record of Uranus' Atmosphere, its Rings, and its Satellites: the WFPC2-ACS Link From molecules to aerosols: observing the haze creation process during Titan's polar summer Using STIS Observations of Auroral Lyman Alpha Line Profiles to Map High-Altitude Winds on Jupiter Binary systems in the Kuiper Belt An Imaging Survey of the Statistical Frequency of Binaries Among Exceptionally-Young Dynamical Families in the Main Asteroid Belt Ceres: High-Resolution Mapping and Determination of Physical Properties Rings of Uranus: Dynamics, Particle Properties and Shepherding Moons Lightning on the Jovian Dayside UVBRI Photometry of Janus and Epimetheus Volatile Abundances and the D/H Ratio in Long-Period Comets All-Sky Archival Zodiacal Background Measurements: Constraints to Kuiper Belt Objects at R=28-60 mag.

Large Programs

Fritz Benedict Michael Gregg Christopher Kochanek Sangeeta Malhotra Matthew Malkan Saul Perlmutter Adam Riess Kailash Sahu

University of Texas at Austin University of California - Davis Smithsonian Institution Astrophysical Observatory Space Telescope Science Institute University of California - Los Angeles Lawrence Berkeley National Laboratory Space Telescope Science Institute Space Telescope Science Institute

Hubble Treasury Programs

Nicholas Scoville Rodger Thompson

California Institute of Technology University of Arizona


Hubble Fellowship Program
Michael Fall, fall@stsci.edu

H

ubble Fellowships are awarded annually to outstanding young scientists engaged in research related to the Hubble mission. The research may be observational--either space -based or ground-based--or theoretical. The Fellowships provide three years of salary and other support at U.S. host institutions of a Fellow 's choice (subject to a maximum of one new Hubble Fellow per institution per year). A selection committee met at the Institute in January 2003 to review about 100 applications for Hubble Fellowships to start in September 2003. The new Fellows are listed in the table below. Hubble Fellows present the results of their research each year at a Hubble Fellows Symposium held at the Institute. The most recent Symposium was held on March 6 and 7, 2003. We plan to select approximately 12 new Hubble Fellows in winter 2003/4 for positions to start in fall 2004. The Announcement of Opportunity, available at http://www.stsci.edu/ stsci/hubblefellow/ao.html , provides instructions for the application process.

2003 New Hubble Fellows
Name
Avishay Gal-Yam Marla Geha Jason Harris Wynn Ho Marc Kuchner Darren Madgwick Michael Muno Jeffrey Newman Nathan Smith Tommaso Treu Risa Wechsler Qingjuan Yu

Ph.D. Institution
Tel Aviv, 2003 Santa Cruz, 2003 Santa Cruz, 2000 Cornell, 2003 Caltech, 2000 Cambridge, 2002 MIT, 2002 Berkeley, 2000 Minnesota, 2002 Pisa/STScI, 2001 Santa Cruz, 2001 Princeton, 2002

Host Institution
Caltech Carnegie Arizona Stanford Princeton LBNL UCLA LBNL Colorado UCLA Chicago Berkeley

The Dumbbell Nebula - M27

A
Image Credit: NASA and the Hubble Heritage Team (STScI/AURA) Acknowledgment: C.R . O 'Dell (Vanderbilt University)

n aging star 's last hurrah is creating a flurry of glowing knots of gas that appear to be streaking through space in this close -up image of the Dumbbell Nebula, taken with NASA's Hubble Space Telescope. The Dumbbell, a nearby planetary nebula residing more than 1,200 light-years away, is the result of an old star that has shed its outer layers in a unique display of color.



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The Local Group: The Universe In A Nutshell
Mario Livio, mlivio@stsci.edu

T

his year 's May Symposium was on the topic of " The Local Group as an Astrophysical Laboratory." The Symposium took place May 5-8, 2003, and it attracted about 130 participants. The choice of topic reflected the fact that observations of the Local Group have reached the point where they can provide a closer look at processes characterizing the universe at large. From observations of the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe (WMAP), we know that the energy density of the universe is dominated by `dark energy ' (about 73%) and non-baryonic dark matter (about 22%). Originally it was thought that the mass in the halos of galaxies might be dominated by Massive Compact Halo Objects (MACHOs), such as brown dwarfs. Microlensing observations towards the Magellanic Clouds revealed that even in the most optimistic case, MACHOs could not constitute more than 5% of the dark matter in the universe, in agreement with the WMAP results. Furthermore, 4 out of the 17 observed microlensing events, for which additional information about location exists, seem to be due to self lensing by Magellanic Clouds stars rather than by MACHOs. Thus, the fraction of mass in MACHOs could be even much smaller. Structure formation is a second topic to which Local Group observations have contributed and will continue to contribute significantly. Current models indicate that the growth of structure in the universe occurred by hierarchical accretion and merger of dark-matter halos. Since galaxy halos should simply be scaled versions of galaxy clusters, a few hundred satellites should accompany galaxies like the Milky Way. The number observed is only a few tens. This increases the importance of studies of high velocity clouds in the Local Group (as potential satellites) and of processes within galaxies, such as feedback from star formation. At the same time, observations of the halo of M31 reported at the Symposium support the idea of past mergers. These observations reveal the presence of a significant population of stars with ages of 6-8 billion years, in contrast to the halo of the Milky Way, where all the ages are between 11 and 13 billion years. This result suggests that M31 may have undergone a major merger some 6 to 8 billion years ago, which threw younger stars from the disk into the halo. Central black holes are a third topic for which observations within our cosmic backyard are important. Black holes have already been discovered at the centers of many galaxies, and collapse into a black hole may be inevitable at the center of very dense stellar systems. The center of the Milky Way afforded a very special treat at the Symposium, with the report that full orbits have now been determined for a few stars around the Galactic black hole, Sgr A. Furthermore, evidence suggests the existence of intermediate -mass (a few thousands to a few tens of thousands solar masses) black holes at the centers of the Galactic globular cluster M15 and the M31 cluster G1. Finally, the Local Group allows a glimpse at star formation in different environments, with different metallicities. Theory suggests that in a hot, metal-free universe, the Initial Mass Function was strongly biased towards massive stars. Starburst regions in the Local Group offer the opportunity to test some of these ideas. Observational and theoretical tools can both now be used on the Local Group to place meaningful constraints on our understanding of the universe.



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Advances with AC S
Roeland P. van der Marel, marel@stsci.edu

F

igure 1 provides a spectacular illustration of the powerful capabilities of the Advanced Camera for Surveys (ACS). In a large Cycle 11 program, Tom Brown and collaborators used the Wide Field Channel (WFC) to take deep images of a field in the halo of the Andromeda galaxy (Messier 31). The panels in the figure show cut- outs that each cover about 1% of the total WFC field of view. Each panel shows a stunning combination of Andromeda halo stars and background galaxies. The results of this program provide the deepest image obtained with Hubble to date. Objects are detected to a limiting magnitude of 31 and there are 300,000 stars in a single ACS/WFC field. The color-magnitude diagram of the stars indicates that approximately one -third of the Andromeda halo stars formed only 6 to 8 billion years ago, which is much younger than the 11-to -13 billion-year age of the stars in the Milky Way 's halo. This finding provides important new clues to the formation of galaxy halos (http://hubble.stsci.edu/ newscenter/archive/2003/15/). On Astronomy Day, May 10, the Institute released a beautiful mosaic of the Helix nebula (NGC 7293; see http://hubble.stsci.edu/newscenter/archive/2003/11/) in conjunction with a variety of other outreach activities. ACS obtained the data for this image during the Leonids

Figure 1: Advanced Camera for Surveys images of fields in the halo of the Andromeda galaxy (Messier 31). Each panel covers about 1% of the total field of view of the Wide Field Channel and shows a stunning combination of Andromeda halo stars and background galaxies. Tom Brown and his collaborators are using these data to study the formation of galaxy halos.

meteor shower in November 2002. At that time we pointed Hubble in the anti-radiant direction of the meteor shower to minimize the risk for potential damage to the telescope. The Helix nebula happens to lie close to this anti-radiant direction. This provided an opportunity for a group of Institute staff and astronomical community members to observe the nebula in a non-proprietary campaign. The Hubble Heritage Team used data from a program aimed at calibration Continued of the ACS polarizer filters to create a spectacular image of the Egg page 18 nebula (http://hubble.stsci.edu/newscenter/archive/2003/09 ).



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Advances with ACS from page 17

ACS will continue to be a focus of attention in Cycle 12. The Institute Director announced the approved programs in April 2003. They are listed on page 8 in this newsletter. ACS observations again make up more than half the accepted programs. The Treasury program of Scoville and collaborators is of particular interest. These investigators will perform a 2 square degree imaging survey (the Cosmic Evolution Survey--COSMOS) with ACS. The survey will study an equatorial field that is accessible to all ground-based telescopes. The data will be non-proprietary and will be available for use by the entire astronomical community. The Cycle 12 TAC also approved four ACS calibration proposals from the astronomical community. We are looking forward to the results from these programs and the improved understanding that they will provide of the instrument. At the Institute, we are continuing to analyze Cycle 11 ACS calibration data. Sixteen supported modes of the ACS High Resolution Channel (HRC) lie in the wavelength regime below 4000 å. We have now created improved flat field reference files for these modes. For those filters that do not have significant red leaks, we used observations of the bright Earth (http://www.stsci.edu/hst/acs/documents/isrs/isr0302.pdf). While the bright Earth is a poor flat field source at optical wavelengths because of structure in the cloud cover, it is a uniform source of diffuse light at shorter wavelengths due to the high optical depth above the cloud layer. Observations of Wolf-Rayet stars are useful for the wavelength calibration of the ACS/WFC G800L grism. Dispersion solutions were derived from such data (http://www.stsci.edu/ hst/acs/documents/isrs/isr0301.pdf ). The results were incorporated into the extraction software `aXe' (http://www.stecf.org/software/aXe/), which is maintained by the Space Telescope European Coordinating Facility. We completed a variety of checks and tests of ACS. We photometrically verified the stability of the shutters for short exposure times and found that they operate within the pre -launch specifications. We also monitored for a potential decrease of ultraviolet sensitivity due to contamination but found none. Photometry of star fields revealed that the point- spread function (PSF) on WFC shows mild variations over the field of view. We found that this is the result of small spatial variations in the thickness of the detector, which affect the charge diffusion properties of the CCD. John Krist developed a model for this effect and included it in the new release of his PSF modeling software Tiny Tim (http://www.stsci.edu/software/tinytim/). We are now analyzing the first external calibration data taken on ACS to measure the effects of Charge Transfer Efficiency (CTE) degradation on stellar photometry. Preliminary results match expectations. For typical observing backgrounds and stellar fluxes, CTE losses on WFC are typically 1 to 2% far from the readout amplifier and readily correctable. However, in worst- case scenarios--faint sources observed with narrow-band filters--CTE losses can be significantly larger. No measurable CTE effects are seen for the HRC at this time. As for other CCD detectors in space, the CTE of ACS is expected to degrade with time. The advent of the Aft Shroud Cooling System (ASCS) during the next servicing mission should mitigate this degradation. The thermal vacuum testing of the ASCS was just completed successfully at Goddard Space Flight Center. Investigators preparing WFC observations for Cycle 12 should pay particular attention to the anticipated growth of hot pixels (see: http://www.stsci.edu/hst/acs/documents/isrs/isr0209.pdf). Proper dithering strategies are required to correct for hot pixels during data reduction, as described in the most recent ACS newsletter ( http://www.stsci.edu/hst/acs/ documents/newsletters/stan0302.html ). This newsletter also provides other important information for those preparing Phase II programs. For example, we are now providing full bias calibrations for the non- default gain settings 2 on WFC and 4 on the HRC, in addition to the default settings (1 and 2, respectively). Also, selection of general subarrays will be available in Cycle 12 and, in some cases, supported. In this context, supported means that bias frame calibrations will be supplied by the Institute for a predefined set of subarrays. Many papers on the calibration of ACS, both from Institute staff and members of the astronomical community, can be found in the proceedings of the 2002 HST calibration workshop, which are now available on-line (http://www.stsci.edu/hst/HST_overview/documents/ calworkshop/workshop2002). As always, the latest news about ACS can be found at http://www.stsci.edu/hst/acs/.



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JWST Mission Replan
Nino Panagia, panagia@stsci.edu

S

purred by a better understanding of the mission costs and available funding, NASA management began an end-to - end examination of the program in November 2002. The `replan' teams involved members from all the development partners and the recently selected Science Working Group (SWG). On January 15, the replan teams reported their conclusions to the JWST project manager Phil Sabelhaus and NASA Headquarters (HQ). If the plan is implemented, the greatest savings will be achieved by ESA providing an Ariane V for the launch vehicle. Northrop Grumman Space Technology (NGST) will develop the integration and test system and the flight software and hardware for the observatory instead of NASA . Integration and test of the science instrument module remains a NASA responsibility. NASA will supply the detectors and support electronics for the ESA near infrared spectrograph. All other instrument projects will procure their own detectors and associated electronics. The observatory-level integration and test plan was simplified to provide additional time for the development and delivery of the science instruments. To further reduce risk, the project decided to reduce the effective area of the primary mirror to 25 square meters (down from 29.4 in the original TRW/Ball proposal). The smaller size meets the baseline science requirements and can be achieved with larger but fewer segments (18 instead of 36). For additional savings, the Canadian Space Agency (CSA) contribution of tunable filters cameras was removed from the Near Infrared Camera (NIRCam) and combined with the Fine Guidance System. While this step did not significantly reduce U.S. costs, it simplifies the working arrangements between CSA and other JWST partners and reduces technical risk in the NIRCam. The Mid-Infrared Instrument (MIRI) team proposed reductions in U.S. contributions to the MIRI development by reducing detector and cryocooler development costs and by increasing software contributions from the European team. The replan is on its way to becoming reality. ESA has proposed to provide the Ariane V launcher for JWST. NASA HQ has reviewed the replan and the cumulative savings and has given approval to move forward. Anne Kinney, the director of the Astronomy and Physics Division at NASA HQ, has repeated her endorsement of the basic JWST instrument capabilities (NIRCam, Near Infrared Spectrometer, and MIRI). With these steps, the Project will complete the replanning exercise and prepare for the key reviews that are required before the JWST team can begin detailed design and development planning (Phase B).

News from the Multimission Archive at STScI (MAST)
Paolo Padovani on behalf of the MAST team, padovani@stsci.edu

I

n early June 2003, Hubble data archive contains 13.8 terabytes of data in about 312,000 science data sets. The archive ingestion rate set another record in February 2003 at almost 19 gigabytes per day. The retrieval rate also set a record the same month, reaching almost 60 gigabytes per day.

New MAST Search Interface Features
We have added three new features to the MAST search interfaces: · Multiple input targets . This feature allows users to search MAST on a list of sky positions or astronomical names, providing a quick and easy way to look for sources having MAST data in an arbitrary catalog. · New preview page for Hubble data . This feature now conforms to the preview pages of other missions by including not only the data preview but also Continued essential information on the observation and the original proposal and page 20 links to published papers.



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Mast from page 19

· High Level Science Products (HLSP) column . The MAST search output page now has an extra column for HLSP, which is for the fully processed images and spectra. A number in this column shows if and how many HLSP related to a given dataset are available and provides links to an HLSP page where one can download the data and access information about them. As usual, send any comments/questions/suggestions/praises you might have to archive@stsci.edu.

Cycle 12 Treasury, Large, & Legacy Archival (TALL) Programs
At the MAST, we are making plans to archive sets of contributed data coming from TALL programs recently awarded time in Cycle 12. As we are doing for the Cycle 11 TALL programs, we will be ingesting into MAST HLSP for these projects as soon as they are made available. The full lists of Cycle 11 and Cycle 12 TALL programs, along with links to the available HLSP and individual program World Wide Web sites, are available at http://archive.stsci.edu/hst/tall.html.

NICMOS Added to the Hubble `Pointings' Interface
By now readers should be familiar with the MAST `pointings' interface (http://archive.stsci.edu/cgi-bin/point ), a tool that allows users to make advanced searches by position and by ranges of the sky in Galactic latitude, ecliptic latitude, right ascension, and declination to which Hubble has been `pointed'. We are pleased to announce that this tool now includes Near Infrared and Multi- Object Spectrometer (NICMOS) data. An example of the queries that are now possible: "How many regions of the sky have been observed at least twice in the J and H band for longer than 1,000 s?" (Answer: 98). Future versions of this tool will include Advanced Camera for Surveys (ACS) data.

StarView News
We recently released StarView 7.2. Current users of StarView are upgraded automatically through the self-update feature. This version of StarView 's most prominent new feature is the Vizier catalog interface. Vizier is the astronomical catalog system supported by SIMBAD at the Centre de Donnees astronomiques de Strasbourg (CDS). Users can now make queries of any catalog available through Vizier and then search for corresponding Hubble observations. We have also simplified user preferences and enabled a `right- click ' option to retrieve specific files. For example, when looking at the reference or On-The -Fly-Reprocessing screen results for a dataset and wanting to retrieve a single reference file, one can now simply `right click ' on the name to request that file. Users can also request specific files by their file name directly from the Retrieval window. StarView is also ready to work with the new Hubble data distribution system, which will be opened to the public in late summer or early fall. We have also included a new and improved version of SpecView for spectral data preview exploration.

Ingest and Distribution Systems Redesign
For the last couple of years, the Institute has been developing a Unix-based replacement for the Data Archive and Distribution System (DADS). As storage and CPU requirements intensified, the Institute also invested in a massive `spinning disk ' storage system, an EMC Symmetrix 8830, and a multi- CPU, multi- domain Sunfire 15K server. Once the software solution for DADS retrievals is operational, users will be able to retrieve subsets of the data (e.g., just the raw data or just the calibrated data). They will also have guest privileges for public data, which means that registration will no longer be necessary for non-proprietary data. DADS should work more reliably and faster because it will retrieve most of the basic data from spinning disk rather than jukeboxes of platters. Internally, we will be able to manage queues more sensibly than `first- come, first- served', which is the only mode currently available.

MAST to Archive Galaxy Evolution Explorer Data
On April 28 the Galaxy Evolution Explorer (GALEX) satellite was successfully launched on a Pegagus XL rocket. Its mission is to survey the whole sky for ultraviolet-bright stars and galaxies to constrain the history of star formation and galaxy evolution back to a redshift of 2. It will also conduct a number of deeper probes over smaller areas. GALEX will provide images and intermediate -resolution spectra of ultraviolet-bright objects in both near- and far-ultraviolet bandpasses. The GALEX Project at JPL (http://www.galex.caltech.edu) will release its data in three stages: an initial (`samplers') Data Release 0 (DR-0) in September 2003, a DR-1 perhaps in late summer of 2004, and a DR-2 at the end of the mission, some 29 months after launch. MAST will be the sole host of GALEX data and serve them at the http://archive.stsci.edu/galex. At this writing, the site is populated with a limited amount of simulated data to allow users to



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become familiar with it. Initially the site will allow the retrieval and browsing of specific data sets, but we expect its primary use to be to permit complex queries (either by point-and- click or Structured Query Language) as well as cross - correlations with Sloan Digital Sky Survey data. By the time of DR-0, we expect to provide the on-line overplotting capability of "ION" (IDL On Line). We look forward to your exercising this system and becoming skillful in manipulating GALEX data in the coming months.

Supernova Shock Wave Paints Cosmic Portrait

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emnants from a star that exploded thousands of years ago created a celestial abstract portrait, as captured in this NASA Hubble Space Telescope image of the Pencil Nebula. Officially known as NGC 2736, the Pencil Nebula is part of the huge Vela supernova remnant, located in the southern constellation Vela. Discovered by Sir John Herschel in the 1840s, the nebula's linear appearance triggered its popular name. The nebula's shape suggests that it is part of the supernova shock wave that recently encountered a region of dense gas. It is this interaction that causes the nebula to glow, appearing like a rippled sheet. Image Credit: NASA and The Hubble Heritage Team (STScI/AURA) Acknowledgment: W. Blair (JHU) and D. Malin (David Malin Images)



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Starburst99 & Mappings --A Perfect Match
Claus Leitherer, leitherer@stsci.edu

T

he Starburst99 evolutionary synthesis code (Leitherer et al. 1999) and its associated website at http://www.stsci.edu/science/starburst99/ are premier tools for modeling star-forming regions containing hot massive stars. Evolutionary and population synthesis codes aim to simulate as many observed properties of resolved and unresolved stellar populations for a predefined set of input parameters, such as the chemical composition, the star-formation history, and the stellar initial mass function. Starburst99 is one of several synthesis codes developed over the past decade, such as GISSEL (Bruzual & Charlot 1993), SED@ (Cervißo & Mas -Hesse 1994), Dial-A-Model (Worthey 1994), PèGASE (Fioc & Rocca-Volmerange 1997), Alexandre Vazdekis' models (Vazdekis 1999), Alberto Buzzoni's database (Buzzoni 2002), or GALEV (Anders & Fritze -v. Alvensleben 2003), to name a few. Links to these and other models are compiled on the website of IAU Commission 35, Stellar Constitution, at http://iau- c35.stsci.edu. The concept of evolutionary synthesis dates back to an influential paper by Tinsley (1968), who pioneered the field of utilizing and testing the predictive power of stellar evolution and atmosphere models.

Figure 1: Starburst99 portal. The link to the new Mappings interface is highlighted in red.

Starburst99 is an ongoing effort at the Institute and owes its capabilities to the contributions of numerous undergraduate and graduate students, postdocs, and collaborators. Its main focus is on hot, massive stars and their main observables. While Starburst99 is a stellar and not a nebular code, there is strong interest in predicting nebular star-formation tracers as well. Star-formation indicators such as the H luminosity of HII regions are widely used as a proxy for the emitted stellar light at far-ultraviolet (far UV) wavelengths (Kennicutt 1998). Predictions for nebular recombination lines are, of course, trivial and are included in the standard Starburst99 application. Modeling non-recombination lines, such as collisionally excited [OIII] 5007 å is outside the scope of Starburst99 and can only be accomplished in combination with photoionization codes. Stasi´ a & Leitherer (1996) made a first attempt in linking Starburst99 to the photoionization nsk code PHOTO. Comparison between predicted and observed emission-line strengths in a sample of HII galaxies suggested ionizing stellar populations with a mass spectrum with close to a Salpeter (1955) slope. Kewley et al. (2001) fed Starburst99 into the Mappings code and pointed out shortcomings of current stellar models when the ionizing radiation field is tested in HII regions. Such tests are particularly revealing when the stellar content is known independently, e.g., from UV spectroscopy. Leitherer et al. (2001) and Robert et al. (2002) discussed how the



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strength and in particular the blueshift of the UV stellar-wind lines can be used to infer the age and mass spectrum of the ionizing stellar population. The underlying physical mechanism is the tight relation between stellar-wind properties (i.e., the line shape and velocity) and luminosity, which is an immediate consequence of a radiatively driven wind. This method has become the standard tool to study stellar populations in the UV (Leitherer 1998). Applying this technique and using the CLOUDY code to model the nebular lines, GonzÀlez Delgado et al. (2002) discussed the potential of simultaneous nebular and stellar modeling and identified areas requiring improvement. We felt the time was finally ripe for developing a simple, robust, and astrophysically sound interface between Starburst99 and a major photoionization code. We opted for Mappings (Sutherland & Dopita 1993), both for physical and practical reasons. Mappings accounts for thermal and non-thermal (shock) energy input, eventually allowing us to link the stellar wind and supernova energy release predicted by Starburst99 with the Mappings shock modeling. On the practical side, a lot of preparatory work had already been done in Lisa Kewley 's thesis, thereby minimizing our effort spent on designing the interface code. Alternatively, Gary Ferland's widely used CLOUDY photoionization code (Ferland et al. 1998) would be an excellent match for Starburst99. Starburst99 and Mappings are mature, independent codes. Therefore we decided to leave the codes on their existing servers at the Institute and CfA and design an interface that would provide an automatic file transfer between the two domains at http://www.stsci.edu and http://www.- cfa.harvard.edu . A new button was added to the familiar Starburst99 portal at the Institute, giving access to the new interface (see Figure 1). The link leads to the new Mappings portal, where the user can specify the model parameters from the input page (Figure 2). This initiates the calculation of a stellar spectral energy distribution with the Starburst99 code at the Institute. Upon completion, the Starburst99 output is automatically transferred to the Mappings

Figure 2: Mappings input page. The user can interactively specify a wide range of stellar, nebular, and dust parameters.

server at CfA and a photoionization model is initialized. Once finished, the photoionization output is returned to the Institute by ftp, and an email notification is sent to the user. The destination directory at the Institute

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Starburst99 from page 23

contains both the nebular output from Mappings and the stellar spectra from Starburst99. While this may sound quite complicated, users do not have to worry about the file transfer between the Institute and CfA . This process occurs entirely behind the scenes. All that needs to be done is to specify the input parameters and wait for an email notification. The Starburst99-Mappings interface became fully operational in December 2002 and has since been widely used by us and by the community at large. An application is shown in Figure 3, where Dopita et al. (2000) computed a grid of diagnostic line ratios to constrain abundances and ionization parameters in HII regions. Those particular calculations made use of older, unblanketed Wolf-Rayet model atmospheres by Schmutz et al. (1992), which produced an overly hard ionizing radiation field for metal-rich Figure 3: Diagnostic plot of [OIII]/Hb vs. [NII]/Ha . stellar populations. In the meantime, a Instantaneous zero-age starburst models computed with new set of fully blanketed models has Starburst99-Mappings. The theoretical grids of ionization become available and was implemented parameter and chemical abundance are shown as well into Starburst99 (Smith et al. 2002). (Dopita et al. 2000). With this upgrade, Starburst99 uses the most advanced stellar model atmospheres currently available for massive, hot stars. We are particularly excited about the prospects of using Starburst99Mappings for the interpretation of infrared spectra of dust- embedded starbursts that will be provided by the upcoming SIRTF mission.

Acknowledgements

Julia Chen's expertise in developing the Starburst99TM-Mappings interface is deeply appreciated. My collaborator Lisa Kewley supported the back-end work at CfA and provided expert advice on issues related to photoionization modeling. We are grateful to the Institute computer support, whose friendly staff helped us overcome numerous roadblocks. This work was made possible by funding from the Director 's Discretionary Research Fund.
References Anders, P & Fritze-v. Alvensleben, U. 2003, A&A, 401, 1063 ., Bruzual A , G., & Charlot, S. 1993, ApJ, 405, 538 Buzzoni, A . 2002, AJ, 123, 1188 Cervißo, M., & Mas-Hesse, J. M. 1994, A&A , 284, 749 Dopita, M. A ., Groves, B. A ., Sutherland, R. S., & Kewley, L. J. 2003, ApJ, 583, 727 Dopita, M. A ., Kewley, L. J., Heisler, C. A ., & Sutherland, R. S. 2000, ApJ, 542, 224 Ferland, G. J., Korista, K. T., Verner, D. A ., Ferguson, J. W., Kingdon, J. B., & Verner, E. M. 1998, PASP, 110, 761 Fioc, M., & Rocca-Volmerange, B. 1997, A&A, 326, 950 n GonzÀlez Delgado, R. M., Leitherer, C., Stasi´ska, G., & Heckman, T. M. 2002, ApJ, 580, 824 Kennicutt, R. C. 1998, ARA&A, 36, 189 Kewley, L. J., Dopita, M. A ., Sutherland, R. S., Heisler, C. A ., & Trevena, J. 2001, ApJ, 556, 121 Leitherer, C. 1998, in Stellar Astrophysics for the Local Group: VIII Canary Islands Winter School of Astrophysics, ed. A . Aparicio, A . Herrero, & F. Sanchez (Cambridge: CUP), 527 Leitherer, C., LeÖo, J. R. S., Heckman, T. M., Lennon, D. J., Pettini, M., & Robert, C. 2001, ApJ, 550, 724 Leitherer, C., Schaerer, D., Goldader, J. D., GonzÀlez Delgado, R. M., Robert, C., Foo Kune, D., de Mello, D. F., Devost, D., & Heckman, T. M. 1999, ApJS, 123, 3 Robert, C., Pellerin, A ., Aloisi, A ., Leitherer, C., Hoopes, C., & Heckman, T. M. 2003, ApJS, 144, 21 Salpeter, E. E. 1955, ApJ, 121, 161 Schmutz, W., Leitherer, C., & Gruenwald, R. 1992, PASP, 104, 1164 Smith, L. J., Norris, R. P. F., & Crowther, P. A . 2002, MNRAS, 337, 1309 Stasi´ska, G., & Leitherer, C. 1996, ApJS, 107, 427 n Sutherland, R. S., & Dopita, M. A . 1993, ApJS, 88, 253 Tinsley, B. 1968, ApJ, 151, 547 Vazdekis, A . 1999, ApJ, 513, 224 Worthey, G. 1994, ApJS, 95, 107



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A Surprise from the Andromeda Halo
Thomas Brown, tbrown@stsci.edu

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ur textbook concept of giant spiral galaxies is largely driven by our own Milky Way, which has an old 1, metal-poor 2 halo of stars, and a younger 3, chemically- enriched 4 stellar disk. However, within the Local Group of galaxies, the Andromeda galaxy offers an important contrast to this picture. Although it is of similar size and Hubble type to the Milky Way, its halo population has a relatively high metallicity 5, as indicated by the colors of its bright red giant stars. These stars offer a good indication of the halo's metallicity, but they tell us little about its age distribution. Thus, without better evidence, the Andromeda halo was assumed to be an old population that underwent more rapid chemical enrichment than the halo of the Milky Way. Accurate ages for stellar populations come from photometry reaching the subgiant branch and main sequence, but these fainter stars have always been beyond the reach of both space-based and ground-based telescopes. However, with the installation of the Advanced Camera for Surveys (ACS) in 2002, we can now resolve these stars in an observing program of reasonable duration. Early in the proposal process, we realized that a detailed observing strategy would be critical to the success of this project. We first considered the required exposure depth. Some team members wanted to resolve stars two magnitudes below an old main sequence turnoff, because that is the level used historically to determine accurate ages in Galactic globular clusters. The halo population of a giant galaxy would be more complicated than that of a globular cluster (where all the stars are the same age and chemical composition), so it made sense that one would want photometry at least as deep as that used to study star clusters. However, the hundreds of Hubble orbits needed to reach that depth seemed unreasonable, even for a scientific goal we felt to be very important. Instead, we chose a goal of 1.5 mag below the turnoff and decided that a large sample of stars could compensate for depth. While accurate photometry requires that images have no more than one star per tens of resolution elements, with the large ACS format we could still comfortably include hundreds of thousands of stars in our halo images. Figure 1: A 25.5 by 36.4 arcsecond subsection of an ACS image We produced artificial ACS images realistically simulating a showing distant background galaxies through the Andromeda halo. broad range of conditions: the effects of the Hubble point- spread function, sky background, detector noise, and various stellar population mixes. From these simulations, we found the level of crowding where we could blindly recover our input population from the photometry. This level of crowding defined a limiting elliptical annulus around Andromeda. We then picked a field along the southeast minor axis within this annulus that also included the globular cluster GC312, thus enabling a secondary goal of studying the age of Andromeda's halo relative to that of one of its clusters. A review of previous Hubble imaging of the chosen field 6 ensured accurate predictions of the crowding. Because we were concerned about the systematic errors that might be introduced by
1 2 3 4 5 6

VandenBerg, D.A ., 2000, ApJS, 129, 315 Ryan, S.G., & Norris, J.E. 1991, AJ, 101, 1865 Fontaine, G., Brassard, P., & Bergeron, P. 2001, PASP, 113, 409 Soubiran, C., BienaymÈ, O., & Siebert, A . 2003, A&A, 398, 141 Mould, J., & Kristian, J. 1986, ApJ, 305, 591 Holland, S., Fahlman, G.G., & Richer, H.B. 1996, AJ, 112, 1035

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using a new Hubble camera, we included images of five Galactic globular clusters with the same ACS filters in order to produce empirical isochrones of old stellar populations, and to calibrate the theoretical isochrones, which could be used to model younger populations. The observations of our Galactic clusters were scattered over the second half of 2002, while the main program in Andromeda executed from 2 Dec 2002 to 11 Jan 2003, obtaining 250 exposures with a total integration time of 3.5 days. The final drizzled images are beautiful (Figure 1), showing thousands of background galaxies through a veil of ~300,000 stars in the halo of Andromeda. The big surprise came from comparisons of our Andromeda color-magnitude diagram to those of the clusters. These show that the Andromeda halo population spans a wide range in both metallicity and age (Figure 2). The metal-poor stars Andromeda are about as old as the stars in M92 (13 Gyr), but those at higher metallicity in Andromeda are younger than those in the clusters. The age spread is indicated by the subgiant branch and main sequence turnoff, which are increasingly brighter in Andromeda than those in the clusters as one moves to higher metallicity. To quantify this further, we used the cluster data to calibrate a library of isochrones7 in the Hubble bandpasses and then fit the Andromeda data using the Figure 2. Left panel: The color-magnitude diagram of the Andromeda halo as observed with the ACS. Completeness limits are marked (the data are 50% complete at Johnson V = 30.7 mag). StarFish code8. This code takes Right panel: Comparison to the ridge lines of five Galactic globular clusters shows that the metal-rich the isochrones, scatters them to populations in Andromeda are significantly younger than those in the clusters. match the photometric errors in the data, and then tries to reproduce the data using a linear combination of the isochrones. We find that no combination of old isochrones (11.5 to 13.5 Gyr) can reproduce the Andromeda data. Instead, a wide range in age (6 to 13.5 Gyr) is required. The best-fit model puts approximately 30% of the Andromeda halo at young ages (6 to 8 Gyr) and high metallicity ([Fe/H] > -0.5). Because the gas in a young giant galaxy rapidly falls into the disk, it seems very unlikely that this newly revealed intermediate -age population can be explained by star formation continuing unassisted in the halo for more than 6 Gyr. A more plausible explanation is a merger with a large satellite galaxy when the universe was approximately half of its present age--or a series of mergers with smaller satellites. The resulting halo would be a mix of stars originally formed in the halo, disrupted disk stars, disrupted satellite stars, and stars formed during the merger(s). It remains to be seen whether halos typically form in a relatively quiescent process, like that in our own Galaxy, or a violent one, like that in Andromeda.
Andromedea Halo from page 25

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VandenBerg, D.A ., & Clem, J.L. 2003, AJ, in press. Harris, J., & Zaritsky, D. 2001, ApJS, 136, 25



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The Omega Nebula

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esembling the fury of a raging sea, this image actually shows a bubbly ocean of glowing hydrogen gas and small amounts of other elements such as oxygen and sulfur. The photograph, tak en by NASA's Hubble Space Telescope, captures a small region within M17, a hotbed of star formation. M17, also known as the Omega or Swan Nebula, is located about 5,500 light-years away in the constellation Sagittarius. Credit: NASA , ESA and J. Hester (ASU)

Contact STScI:
The Institute's website is: http://www.stsci.edu Assistance is available at help@stsci.edu or 800-544-8125. International callers can use 1-410-338-1082. For current Hubble users, program information is available at: http://presto.stsci.edu/public/propinfo.html. The current members of the Space Telescope Users Committee (STUC) are: Debbie Elmegreen (chair), Vassar College, elmegreen@vassar.edu Debbie Elmegreen, (CHAIR) Vassar College David Axon, U. of Hertfordshire Marc Davis, U.C. Berkeley James Dunlop, U. Edinburgh Martin Elvis, Harvard-Smithsonian Holland Ford, JHU Karen Meech, Institute for Astronomy Peter Nugent, Lawrence Berkeley Laboratory Karl Stapelfeldt, JPL John Stocke, U. Colorado Lisa Storrie-Lombardi, Caltech

ST-ECF Newsletter

T

he Space Telescope - European Coordinating Facility publishes a newsletter which, although aimed principally at European Space Telescope users, contains articles of general interest to the HST community. If you wish to be included in the mailing list, please contact the editor and state your affiliation and specific involvement in the Space Te lescope Project. Richard Hook (Editor)

The Space Telescope Science Institute Newsletter is edited by Robert Brown, rbrown@stsci.edu, who invites comments and suggestions. Technical Lead: Christian Lallo, clallo@stsci.edu Design: Krista Wildt, wildt@stsci.edu To record a change of address or to request receipt of the Newsletter, please send a message to addr-chgsn@stsci.edu.

Space Telescope European Coordinating Facility Karl Schwarzschild Str. 2 D-85748 Garching bei MÝnchen Germany E-Mail: rhook@eso.org



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Contents:
Cycle 12 Cycle Cycle Cycle Cycle 12 12: 12: 12: Results . . . . . . . . . . . . . . . . . TAC and Panel Members . . . Statistics . . . . . . . . . . . . . . . Approved Observing Programs Institute News Director 's Perspective . . . . . . Hubble Fellowship Program . . The Local Group: The Universe Advances with ACS . . . . . . . JWST Mission Replan . . . . . . MAST News at STScI . . . . . . .. .. in .. .. .. . . a . . . ....... ....... Nutshell ....... ....... ....... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 .15 .16 .17 .19 .19 .... .... .... ... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 .5 .6 .8

Calendar
JWST Science Working Group at the Institute . . . . . . . . . . . . . . .October 1-2, 2003 STUC at Institute . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .November 6-7, 2003

Institute Science Starburst99 & Mappings--A Perfect Match . . . . . . . . . . .22 A Surprise from the Andromeda Halo . . . . . . . . . . . . . . . .25

Contact STScI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .27 Calendar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .28

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